A5022896239- Stellar, planetary, and galactic studies
- Astronomy and Astrophysical Research
- Astrophysics and Star Formation Studies
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Atmospheric Ozone and Climate
- Calibration and Measurement Techniques
- Spectroscopy and Laser Applications
- Pulsars and Gravitational Waves Research
- Adaptive optics and wavefront sensing
- Photocathodes and Microchannel Plates
- Atomic and Molecular Physics
- Scientific Research and Discoveries
- History and Developments in Astronomy
- Solar and Space Plasma Dynamics
- High-pressure geophysics and materials
- Heat shock proteins research
- Toxin Mechanisms and Immunotoxins
- Cardiac and Coronary Surgery Techniques
- Geophysics and Gravity Measurements
- Advanced Chemical Physics Studies
- Surface and Thin Film Phenomena
- Cardiac Valve Diseases and Treatments
University of Tübingen
2012-2022
Max Planck Institute for Astrophysics
2012-2021
Friedrich-Alexander-Universität Erlangen-Nürnberg
2002-2020
Boehringer Ingelheim (United States)
2016
Boehringer Ingelheim (Germany)
2009-2012
University of Arizona
2010-2011
University of Illinois Urbana-Champaign
2010-2011
University of Leicester
2010
University of Valparaíso
2010
Institut d'Estudis Espacials de Catalunya
2010
The introduction of limited approaches to the heart and avoidance cardiopulmonary bypass (CPB) aim reduce invasiveness CABG by decreasing systemic release inflammatory cytokines, such as tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-8, well anti-inflammatory agent IL-10. This study compares humoral immune response in patients undergoing with standard, minimally invasive, "off-pump" techniques.Thirty were divided into 3 operative groups: full sternotomy approach plus CPB (group...
Ribosome-associated Trigger Factor (TF) and the DnaK chaperone system assist folding of newly synthesized proteins in Escherichia coli. Here, we show that TF share a common substrate pool vivo. In TF-deficient cells, deltatig, depleted for DnaJ amount aggregated increases with increasing temperature, amounting to 10% total soluble protein (approximately 340 species) at 37 degrees C. A similar population tig+ albeit much lower extent. Ninety-four isolated from DnaK- DnaJ-depleted deltatig...
Non-local Thermodynamic Equilibrium (NLTE) calculations of hot white dwarf (WD) model atmospheres are the cornerstone modern flux calibrations for Hubble Space Telescope (HST) and CALSPEC database. These theoretical spectral energy distributions (SEDs) provide relative vs. wavelength, only absolute level remains to be set by reconciling measured Vega in visible with Midcourse Experiment (MSX) values Sirius mid-IR. The most recent SEDs calculated \textsc{tlusty} \textsc{tmap} NLTE atmosphere...
The precise analysis of properties planetary nebulae is strongly dependent on good models for the stellar ionizing spectrum. Observations in UV – X-ray wavelength range as well NLTE model atmosphere calculations spectra their exciting stars have shown that neither blackbody fluxes nor "standard" which are composed out hydrogen and helium only approximations. Strong differences between synthetic from these compared to observed at energies higher than 54 eV ( ground state) can be ascribed...
Excess emission from a pointlike source coincident with the central star of Helix Nebula is detected Spitzer at 8, 24, and 70 μm. At 24 μm, superposed on an extended diffuse region. While [O IV] 25.89 μm line contributes to emission, 10-35 spectrum shows strong thermal continuum. The excess most likely originates dust disk blackbody temperatures 90-130 K. Assuming simple optically thin debris model, distributed in ring between ~35 ~150 AU star, possibly arising collisions Kuiper Belt-like...
Swift X-ray observations of the ∼60 day supersoft phase recurrent nova RS Ophiuchi (RS Oph) 2006 show progress nuclear burning on white dwarf (WD) in exquisite detail. First seen 26 days after optical outburst, this started with extreme variability likely due to variable absorption, although intrinsic WD variations are not excluded. About 32 later, a steady decline count rate set in. NLTE model atmosphere spectral fits during that effective temperature increases from ∼65 eV ∼90 phase,...
Stars are generally spherical, yet their gaseous envelopes often appear non-spherical when ejected near the end of lives. This quirk is most notable during planetary nebula phase these become ionized. Interactions among stars in a binary system suspected to cause asymmetry. In particular, precessing accretion disk around companion believed launch point-symmetric jets, as seen prototype Fleming 1. Our discovery post common-envelope nucleus 1 confirms that this scenario highly favorable....
We perform nonlocal thermodynamic equilibrium (NLTE) model atmosphere analyses of the three hottest hypervelocity stars (space velocities between ≈1500–2800 km s −1 ) known to date, which were recently discovered spectroscopically and identified as runaways from Type Ia supernovae. The (J0546+0836, effective temperature T eff = 95 000 ± 15 K, surface gravity log 𝑔 5.5 0.5) has an oxygen-dominated with a significant amount carbon (C 0.10 0.05, O 0.90 mass fractions). Its mixed...
The ribosome-associated Trigger Factor (TF) cooperates with the DnaK system to assist folding of newly synthesized polypeptides in Escherichia coli. TF unifies two functions one promote proper protein vitro. First, as a chaperone it binds unfolded substrates, thereby preventing aggregation and supporting productive folding. Second, catalyzes cis/trans isomerization peptidyl-prolyl bonds, which can be rate-limiting step Here, we investigated whether isomerase (PPIase) function is essential...
Trigger Factor (TF) is the first chaperone that interacts with nascent chains of cytosolic proteins in Escherichia coli. Although its activity requires association ribosomes, TF present vivo a 2 3 fold molar excess over ribosomes and fraction it not ribosomeassociated after cell lysis. Here we show follows threestate equilibrium. Size exclusion chromatography, crosslinking analytical ultracentrifugation revealed uncomplexed dimerizes an apparent Kd 18 M. Dimerization mediated by Nterminal...
Escherichia coli trigger factor (TF) and DnaK cooperate in the folding of newly synthesized proteins. The combined deletion TF-encoding tig gene dnaK causes protein aggregation synthetic lethality at 30 degrees C. Here we show that DeltatigDeltadnaK52 cells is abrogated either by growth below C or overproduction GroEL/GroES. At 23 were viable showed only minor aggregation. Overproduction GroEL/GroES, but not other chaperones, restored suppressed including proteins >/=60 kDa, which normally...
In eukaryotes, newly synthesized proteins interact co-translationally with a multitude of different ribosome-bound factors and chaperones including the conserved heterodimeric nascent polypeptide-associated complex (NAC) Hsp40/70-based chaperone system. These are thought to play an important role in protein folding targeting, yet their specific ribosomal localizations, which prerequisite for functions, remain elusive. This study describes localization NAC molecular details by is able contact...
We report on the first detection of noble gases krypton (Z = 36) and xenon (54) in a white dwarf. About 20 Kr vi– vii Xe lines were discovered ultraviolet spectrum hot DO-type dwarf RE 0503−289. The observations, performed with Far Ultraviolet Spectroscopic Explorer, also reveal highly ionized photospheric from other trans-iron group elements, namely Ga (31), Ge (32), As (33), Se (34), Mo (42), Sn (50), Te (52), I (53), which gallium molybdenum are new discoveries dwarfs, too. For Xe, we an...
While the near-infrared wavelength regime is becoming more and important for astrophysics there a marked lack of spectrophotometric standard star data that would allow flux calibration such data. Furthermore, calibrating medium- to high-resolution \'echelle spectroscopy challenging even in optical range, because available are often too coarsely sampled. We will provide reference users derive response curves from 300nm 2500nm spectroscopic medium high resolution, including those taken with...
ABSTRACT In Escherichia coli , the ribosome-associated chaperone Trigger Factor (TF) promotes folding of newly synthesized cytosolic proteins. TF is composed three domains: an N-terminal domain (N), which mediates ribosome binding; a central (P), has peptidyl-prolyl cis/trans isomerase activity and involved in substrate binding vitro; C-terminal (C) with unknown function. We investigated contributions individual domains (N, P, C) or combinations (NP, PC, NC) to vivo vitro. All fragments...
We have discovered lines of highly ionized fluorine ( and ) in the far-UV spectra extremely hot = 85 000–150 000 K) post-AGB stars. Our sample comprises H-rich central stars planetary nebulae as well H-deficient PG1159 performed non-LTE calculations find strong F overabundances (up to 10-4 by mass, i.e., 250 times solar) a number stars, while is essentially solar Since are believed exhibit intershell matter preceding AGB phase on their surface, chemical analyses allow for direct insight into...
Half a year after its outburst in September 2002, nova V4743 Sgr evolved into the brightest supersoft X-ray source sky with flux maximum around 30A. We calculated grids of synthetic energy distributions (SEDs) based on NLTE model atmospheres for analysis hottest white dwarfs and present result fits to Chandra XMM-Newton grating spectra outstanding quality, exhibiting prominent resonance lines C V, VI, N VII, O VII absorption. The reached highest effective temperature (Teff = 740 +/- 70kK)...
H-rich, DA-type white dwarfs are particularly suited as primary standard stars for flux calibration. State-of-the-art NLTE models consider opacities of species up to trans-iron elements and provide reliable synthetic stellar-atmosphere spectra compare with observation. We establish a database theoretical stellar standards that easily accessible via web interface. In the framework Virtual Observatory, German Astrophysical Observatory developed registered service TheoSSA. It provides easy...
Linagliptin is a xanthine-based dipeptidyl peptidase (DPP)-4 inhibitor that now available in numerous countries worldwide for the treatment of type 2 diabetes mellitus (T2DM). The aim this study was to evaluate further mechanisms underlying improvements glycemic control observed with linagliptin. effects linagliptin on DPP-4, pharmacodynamic parameters, and versus placebo were assessed patients inadequately controlled T2DM.Patients phase 2a, multicenter, randomized, double-blind,...